• 한국정보과학회논문지:컴퓨팅의 실제 및 레터
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• 제11권6호
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• pp.465-476
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• 2005

본 논문에서는 Cactus와 Globus 기반의 그리드 컴퓨팅 환경에서 응용프로그램 수준의 체크 포인팅을 사용한 동적 재구성(Dynamic Reconfiguration) 기법을 새로이 제안하였다. 기존의 동적 재구성은 특정 하드웨어와 운영체제에 종속적이었으나 제안한 방법은 특정 하드웨어와 운영체제의 지원 없이 동적재구성이 가능하고 응용프로그램도 동적 재구성을 고려할 필요 없이 프로그래밍이 가능하다. 제안한 동적 재구성 기법에서 초기 연산자원의 구성을 갖고 실행되는 작업은 실행 중에 동적으로 발견된 새로운 연산자원을 포함하여 계속 연산을 수행한다. 본 연구에서 제안된 방법은 새롭게 발견된 연산자원의 프로세서 성능과 유휴 메모리를 고려하여, 해당 연산자원을 수행중인 연산에 포함할 것인가 여부를 결정한다 연산중 연산 결과의 실시간 가시화를 가능하도록 하고 운영체제에 종속적이지 않은 응용프로그램 수준의 체크 포인팅 기법을 사용하여 중간 연산결과를 저장한다. 새롭게 발견된 유휴사이트, 유휴프로세서를 포함하도록 연산자원의 구성을 재구성한 후 체크 포인팅 파일을 사용하여 작업을 계속 실행한다. 제안한 동적 재구성 기법은 K*Grid 환경에서 연산시간을 단축함을 확인하였다.

• International Journal of Contents
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• 제10권4호
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• pp.11-17
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• 2014

The influence of acquisition environment on music score images captured by a camera has not yet been seriously examined. All existing Optical Music Recognition (OMR) systems attempt to recognize music score images captured by a scanner under ideal conditions. Therefore, when such systems process images under the influence of distortion, different viewpoints or suboptimal illumination effects, the performance, in terms of recognition accuracy and processing time, is unacceptable for deployment in practice. In this paper, a novel, lightweight but effective approach for dealing with the issues caused by camera based music scores is proposed. Based on the staff line information, musical rules, run length code, and projection, all regions of interest are determined. Templates created from inverse filter are then used to recognize the music symbols. Therefore, all fragmentation and deformation problems, as well as missed recognition, can be overcome using the developed method. The system was evaluated on a dataset consisting of real images captured by a smartphone. The achieved recognition rate and processing time were relatively competitive with state of the art works. In addition, the system was designed to be lightweight compared with the other approaches, which mostly adopted machine learning algorithms, to allow further deployment on portable devices with limited computing resources.

• 대한임베디드공학회논문지
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• 제11권4호
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• pp.243-249
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• 2016

Energy-harvesting nodes in wireless sensor networks(WSNs) can be exhausted due to a heavy workload even though they can harvest energy from their environment. On contrast, they can sometimes fully charged, thus waste the harvested energy due to the limited battery-capacity. In order to utilize the harvested energy efficiently, we introduce a selective data compression and transmission range control scheme for energy-harvesting nodes. In this scheme, if the residual energy of a node is expected to run over the battery capacity, the node spends the surplus energy to exploit the data compression or the transmission range expansion; these operations can reduce the burden of intermediate nodes at the expanse of its own energy. Otherwise, the node performs only basic operations such as sensing or transmitting so as to avoid its blackout time. Simulation result verifies that the proposed scheme gathers more data with fewer number of blackout nodes than other schemes by consuming energy efficiently.

• 산업경영시스템학회지
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• 제35권4호
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• pp.83-97
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• 2012

In this paper, we consider a single-manufacturer single-buyer supply chain problem where a single manufacturer purchases and processes raw materials into a family of items in order to deliver a family of items to a single buyer at a fixed interval of time for effective implementation of Just-In-Time Purchasing. An integrated multi-item lot-splitting model of facilitating multiple shipments in small lots between buyer and manufacturer is developed in a JIT Purchasing environment. Previous research on the integrated model assumed that the manufacturer orders raw materials m (integer) times for every production run (lot multiplier policy for the raw material). In this paper, we consider a generalized policy in the replenishment of raw materials, allowing lot multiplier policy and lot splitting policy. An iterative solution procedure is developed to find the order interval for finished goods and raw materials, and number of shipments between buyer and manufacturer. We show by numerical example that when the integrated policy is adopted by both buyer and manufacturer in a cooperative manner, both parties can benefit.

• 전기전자학회논문지
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• 제19권2호
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• pp.148-154
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• 2015

차량 전장시스템은 매 순간마다 정확한 인식을 통하여 사용자에게 정확한 경보를 전달해야 한다. 따라서 차량 영상 인식 알고리즘을 적용하기 위하여 빠른 전처리 시스템이 필요하다. 본 논문은 운전자 보조 시스템의 영상 처리를 목적으로 histogram equalization과 편차를 이용한 bilateral Filter를 사용하여 blur 영상을 보정하는 방법에 대해서 제안하였다. 제안한 시스템은 영상 스케일, 평활화, 노이즈 필터, 윤곽선 추출 순으로 총 5단계로 구성되며, bilateral filter의 과 값을 운전자 보조 시스템에서 나타나는 도로의 주행 현상에 적합하게 추출하여 10픽셀 이하의 blur를 기존의 방법들보다 빠르게 처리하였다. 실험 결과는 MATLAB을 사용하여 소요시간 및 PSNR을 구하였으며 기존의 방법과 비교하여 본 논문의 결과가 처리속도가 빠름을 입증하였다.

• International Journal of Ocean System Engineering
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• 제1권1호
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• pp.52-59
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• 2011

A prototype radar display unit was implemented using inexpensive off-the-shelf components, including a nonlinear estimation algorithm for the target tracking in a clutter environment. Two custom designed boards; an analog signal processing board and a DSP board, can be plugged into an expansion slot of a personal computer (PC) to form a maritime radar display unit. Our system provided all the functionality specified in the International Maritime Organization (IMO) resolution A422(XI). The analog signal processing board was used for A/D conversion as well as rain and sea clutter suppression. The main functions of the DSP board were scan conversion and video overlay operations. A host PC was used to run the tracking algorithm of targets in clutter, using the discrete-time Bayes optimal (nonlinear, and non-Gaussian) estimation method, and the graphic user interface (GUI) software for Automatic Radar Plotting Aid (ARPA). The proposed tracking method recursively found the entire probability density function of the target position and velocity by converting into linear convolution operations.

• International Journal of Computer Science & Network Security
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• 제23권10호
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• pp.169-178
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• 2023

Wireless sensor network is wieldy use for IoT application. The sensor node consider as physical device in IoT architecture. This all sensor node are operated with battery so the power consumption is very high during the data communication and low during the sensing the environment. Without proper planning of data communication the network might be dead very early so primary objective of the cluster based routing protocol is to enhance the battery life and run the application for longer time. In this paper we have comprehensive of twenty research paper related with clustering based routing protocol. We have taken basic information, network simulation parameters and performance parameters for the comparison. In particular, we have taken clustering manner, node deployment, scalability, data aggregation, power consumption and implementation cost many more points for the comparison of all 20 protocol. Along with basic information we also consider the network simulation parameters like number of nodes, simulation time, simulator name, initial energy and communication range as well energy consumption, throughput, network lifetime, packet delivery ration, jitter and fault tolerance parameters about the performance parameters. Finally we have summarize the technical aspect and few common parameter must be fulfill or consider for the design energy efficient cluster based routing protocol.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2004년도 춘계학술대회 논문집
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• pp.43-48
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• 2004

인터넷 환경에서 실시간 서비스에 대한 제공을 위해 제안된 RTP(Real-time Transport Protocol)는 실시간 전송 프로토콜로서 스트림형 데이터 전송을 목적으로 한 프의토콜이다. RTP는 기본적으로 RTCP(Real-time Transport Control Protocol)와 쌍을 이루어 동작하며, RTCP는 현재 네트워크의 상태 정보를 전달한다. RTP는 종단 시스템에서 실행되고, 디멀티플랙싱을 제공하는 전송 프로토콜의 중요한 특성을 가지고 있다. 또한, TCP 같은 전송 프로토콜에서 제공하지 못하는 신뢰성과, 프로토콜에 정의된 흐름/혼잡제어를 제공한다. 본 논문에서는 RTP상에서 동작하는 Differentiated Service의 개념과 구조를 살펴보고, Differentiated Service상에서 효율적인 패킷전송을 위해 CBQ(Class-Based Queuing)을 사용한 패킷 전송 모델의 파라미터를 설정함으로써 각자의 서비스 큐를 적절하게 제어하고, WRR(Weighted Round Robin)과 PRR(Packet-by-packet Round Robin) 같은 패킷 스케줄링 기법을 통해서 모든 서비스 클래스들이 기아현상을 경험하지 않고 공평한 스케줄링이 이루어지도록 컴퓨터 모의실험을 통해 성능을 확인한다.

• 한국환경과학회지
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• 제7권6호
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• pp.867-873
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• 1998

Laboratory study was conducted to provide basic data for operating anaerobic sequencing batch reactor(ASBR) process for treatment of nightsoil. The experiments were concerned with digestion characteristics, settleabiltity and dewaterability of digested sludge in ASBR system. Completely-mixed dally-fed control reactor without solid-liquid separation step was also operated to evaluate the baseline performance since the nature of nightsoil was changed with time. In all case, gas production from the ASBR shows 1.3 to 1.44 times higher than that from control, in spite of almost similar trend in organics removal. During thickening period, remarkable decrease in surface settling velocity was observed at the ASBRs compared with the control. In case of the ASBR run, flotation of mixed digested sludge was not occurred. Also, ultimate thickened volume of ASBRs increased 1.2~1.5 times compared with control. Dewaterability of digested sludge without conditioning decreased when the completely-mixed daily-fed reactor for ASBR run was converted to the ASBR. However, improvement of dewaterability of digested sludge from the ASBRs was observed as a result of addition of FeCl$_3$ to digested sludge for conditioning.

• 한국환경농학회지
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• 제33권4호
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• pp.314-320
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• 2014

BACKGROUND: Run off from agricultural sites contaminates water bodies with nitrogen which is toxic and causes eutrophication when excessively accumulated. Hence, the interest in monitoring nitrogen toxicity in aquatic environment has been continuously increasing. METHODS AND RESULTS: To detect a real time toxicity of various nitrogen compounds, we applied biomonitoring method (biosensor) based on sulfur-oxidizing bacteria (SOB). The toxicity biomonitoring test was conducted in semi-continuous mode in a reactor filled with sulfur particles (2~4 mm diameter) under aerobic condition. Relative toxicity was simply determined by measuring the change in electrical conductivity (EC). Various nitrogenous compounds at different concentrations were evaluated as a potential toxic substance. Nitrite was found to be very toxic to SOB with a 90% inhibition even when the concentration as low as 3 mg/L. However, nitrate and ammonia have any inhibitory effect on SOB's activity. CONCLUSION: The biosensor based on SOB responded sensitively to nitrite even at substantially low concentrations. Therefore, it can be used as a reliable biological alarm system for rapid detection of contaminants due to its simplicity and sensitive nature.